This invention relates generally to printers and plotters, and more specifically to printheads such as thermal inkjet cartridges mounted on a carriage which traverses back and forth across media in either sheet or roll form.
Thermal inkjet printers/plotters typically mount removable print cartridges on a carriage for traversing back and forth across a sheet of media which is periodically advanced along the media movement axis (typically called the X-axis). When the printer/plotter is used for monochrome printing, a single print cartridge is used, and the width of a printing swath is determined by the actual width of the nozzle portion of the print cartridge. When the printer/plotter is used for color printing, one or more additional print cartridges are mounted on the carriage. However, such additional cartridges have been mounted for straight-line alignment with each other along the carriage axis (typically called the Y-axis), and therefore the swath width is still determined by the actual width of the nozzle portion of the print cartridge. In some instances a single print cartridge may have multiple nozzle sets. For example, in the PaintJet family of thermal inkjet printers of Hewlett-Packard Company, the black print cartridge has three nozzle sets which provide a wider printing swath than the corresponding color print cartridge which can be mounted alongside the black print cartridge in a straight-line alignment in the Y direction.
When thermal inkjet printing is used in large format printers/plotters, the throughput limitation due to swath width makes it difficult to compete with more expensive printers/plotters such as laser printers, electro-static plotters and the like. Accordingly, there is a need to provide a large format printer/plotter which increases throughput without having to design a new enlarged print cartridge.